DEF CON 28 Safe Mode · United States · 2020

DEF CON 28 Safe Mode Badge

Cassette-tape puzzle badge

A LosT / 1o57-designed DEF CON 28 Safe Mode support badge built as an audio cassette in a jewel case, with puzzle material spread across the A/B tape audio, lanyard characters, printed liner notes, media-server contents, and DEF CON forum solving space.

DEF CON United States Safe Mode Virtual Event Cassette Tape Analog Badge Audio Challenge Lanyard Puzzle LosT North America

EventDEF CON 28 Safe Mode

SeriesDEF CON

LocationVirtual / online

CountryUnited States

People

Authors & Credits

Safe Mode announcement and support-role publisher

Dark Tangent

The forum badge-challenge post and Safe Mode support-role posts were published under Dark Tangent's DEF CON account.

Source

badge and mystery challenge creator

LosT / 1o57

DEF CON's forum names LosT as the badge creator and Hackaday documents 1o57 messages in the liner-note trail.

Source

cassette-badge field reporter

Mike Szczys

Author of the Hackaday hands-on report used for physical cassette, liner, lanyard, and audio-challenge observations.

Source

event and badge issuer

DEF CON Communications

DEF CON archive material announces Safe Mode, the cassette badge, and the remote-event support context.

Source

Why It Mattered

It documents DEF CON's pandemic-era adaptation of badge culture: the conference moved online, attendance was free, and the optional physical badge became a mailed analog artifact that carried the badge challenge without relying on an in-person line or powered hardware.

Hardware

Hackaday documented a real purple-tinted cassette tape in a shrink-wrapped jewel case, side A/B markings, masked DEF CON logo, side-label art, lanyard material, and folded liner notes. The physical artifact is intentionally analog, so this record does not claim a microcontroller, firmware, LEDs, or battery.

Software & Apps

The challenge material is audio and encoding rather than badge firmware. Public sources document tones, a number-station-like opening, music, character-color and lanyard ciphers, downloadable media-server tape contents, and forum collaboration around the pre-con badge challenge.

Lore

Safe Mode made DEF CON 28 remote and free, with Human Plus and badge purchases used as support paths. The cassette badge echoed DEF CON 23's record badge while turning mailed media, liner art, and community forum solving into the event's official badge surface.

Lifecycle

Add-ons & Upgrades

analog badge historical

Cassette tape badge

The Safe Mode badge was a real cassette tape in a jewel case, with side A/B markings, label art, and audio content that formed part of the challenge.

Compatibility: DEF CON 28 Safe Mode Badge

Source

media challenge historical

Printed liner and audio puzzle

Folded liner notes and the cassette audio carried track-list, color, character, tone, and number-station-style clues for remote badge solving.

Compatibility: DEF CON 28 Safe Mode Badge

Source

physical challenge historical

Lanyard cipher surface

The lanyard carried unusual character strings and is identified by official forum and writeup sources as one of the challenge surfaces included with the badge.

Compatibility: DEF CON 28 Safe Mode Badge

Source

Operational history

Issues & Camp Impact

audio-artifact caveat note

Public sources document the cassette, liner, lanyard, and media-server availability, but this pass does not mirror or audit every audio file, transcript, tape variant, or final puzzle solution branch.

The catalogue records the verified analog badge surfaces and leaves complete audio forensics for a later artifact-level pass.

Confidence: source-backed but incomplete
Status: needs deeper artifact inventory
Timeframe: current DEF CON 28 pass
Source note: DEF CON forum challenge post, Hackaday hands-on article, and CIRCUITS TO KERNEL writeup.

missing rights-cleared image note

No local DEF CON 28 cassette-badge photo has been added because article and writeup images have not been paired with a complete reuse basis, attribution string, and processing record for this catalogue.

The entry remains image-free rather than copying Hackaday or personal writeup photography without provenance.

Confidence: local project policy
Status: needs licensed original replacement
Timeframe: current catalogue build
Source note: badge.gallery image policy, Hackaday article images, and independent challenge-writeup images.

Resources

DEF CON 28 InfoconDB record event metadata · InfoconDB source for DEF CON 28 virtual location, August 6-9, 2020 dates, free general admission, and official conference links. DEF CON 28 Safe Mode archive event archive mirror · Archived DEF CON Safe Mode page source for the in-person cancellation, August 6-9 online event context, optional Human Plus support model, and official cassette-badge announcement. DEF CON 28 badge challenges writeup challenge writeup · Independent writeup source documenting the lanyard, cassette tape, liner-front, liner-back, character-color puzzle, and challenge timing. Pandemic DEF CON badge hands-on field report · Contemporary Hackaday source documenting the physical cassette, jewel case, lanyard, liner notes, tones, number-station-like audio, and collaboration project. Safe Mode Badge Challenge forum official forum thread · DEF CON forum source proving badge purchase/support context, LosT creator attribution, challenge surfaces, and media.defcon.org cassette-content availability.

Sources

CIRCUITS TO KERNEL: DEF CON 28 - Badge Challenges Retrieved 2026-05-15 · Challenge writeup source for lanyard, cassette, liner-front, liner-back, color-character puzzle observations, and puzzle-start timing. DEF CON Forums: Welcome to the pre-con Safe Mode Badge Challenge forum! Retrieved 2026-05-15 · Official forum source for badge creator LosT attribution, cassette/lanyard/liner challenge scope, and media-server availability for cassette contents and liner notes. DEF CON archive mirror: DEF CON 28 Safe Mode archive Retrieved 2026-05-15 · Event archive source for Safe Mode cancellation/online-event context, Human Plus support framing, and the official announcement that the badge was a LosT-created cassette tape. Hackaday: Hands-On: The Pandemic DEF CON Badge Is An Audio Cassette Retrieved 2026-05-15 · Contemporary source for the physical cassette badge, jewel case packaging, lanyard characters, liner-note clues, audio tones, number-station-like opening, and Hackaday.io collaboration context. InfoconDB: DEF CON 28 (2020) Retrieved 2026-05-15 · Event metadata source for virtual location, August 6-9, 2020 dates, free general admission, and official DEF CON 28 links.